Answer:
Jill made an error when writing the factored expression.
Gary gets 4 marbles, because 12/3 is 4. So for the ratio 3:1 to apply, Jo gets 12 marbles and Gary gets 4.
It would be 8 because 8+4=12
I am not sure but I think the answer is B.
3x + 4y = 16 Subtract 4y from both sides. Put brackets around the 2 terms on the right.
3x + 4y - 4y = (16 - 4y)
3x = (16 - 4y) Divide by 3
Answer That's B.